I have a quite basic question regarding Qlik Sense (server). After uploading and publishing an App, users can access it and create their own sheets with their own objects and stories and publish them afterwards. So far so good. But what if a user wants to modify an existing sheet? What if he wants to delete it? Is there any special permission for doing that?

At the moment the owner of the app will have to duplicate the app, then modify it and finally publish it again. It's not possible to change a published app. This will change in a future release of Qlik Sense so it becomes easier to change apps.

The user will need to be the owner of the app. And if he republished it under the same name then the original won't have to be removed manually. It's possible to export the app from the QMC. If necessary it can be retrieved from the file system of the server, but then you'd need to know its unique identifier. The apps are not stored by app name, but with the unique identifier as its file name.

However, I'm not able to publish the app after modifying it. I duplicate the app and the duplicated app goes to "My work". This creates another app in the Apps section of the QMC. But right-clicking on the duplicated app does not suggest anything related to publishing it.